BQ51003: Vout does not appear.

KIM Andy

Part Number: BQ51003

My client is developing Smart Ring, a ring-type healthcare service.

Because it is a low-watt product, it has been confirmed that the winding value of Rx is arbitrarily designed with PCB pattern.

It has been confirmed that the Vrect voltage is 7V initially. Thereafter, it is confirmed that the output voltage is 5 V or more, but the Vout voltage is not output at all.

The on time of switching seems to be very short.

It was confirmed that 7V required for initial start-up occurred.
Is there a problem with PCB design or something like this? Please let me know what you need to check.

over 7 years ago

0 Bill Johns over 7 years ago

TI__Guru* 77046 points

The Schematic looks ok but somethings to check on:
1.) Check the coil tuning -- C54/C58/C59 total 76nF this would be valid for a 33uH coil and PCB coils are often lower.
2.) FOD turning -- Exchange R38/R39 value, higher value for R39 (FOD) will add margin to the FOD calculation and prevent problems.
3.) Remove R37 -- not needed at this time.
4.) Can you send scope capture of waveform at RECT pin

0 KIM Andy over 7 years ago in reply to Bill Johns

Expert 2530 points

Hi
thank you for your quick reply.
Can you tell me about the FOD calibration procedure? I have checked the contents of the datasheet, but I have been told to contact TI. please check.
I installed the FOD calibration program but it does not work. Could you provide an operation manual?

Best Regards

0 Bill Johns over 7 years ago in reply to KIM Andy

TI__Guru* 77046 points

Hi
The operating manual is part of the FOD GUI and can be accessed from the tool bar top right.

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BQ51003: Vout does not appear.